VHDL standards

Provides a brief overview of VHDL-related standards. The IEEE approved the original VHDL standard (IEEE Std 1076) in 1987, then revised and significantly enhanced it in 1993. In 2000, an interim edition added concurrency control features for shared variables. The new features, called protected types, are based on the idea of monitors seen in concurrent programming languages. The standard is now nearing the final stages of a further revision process, and is headed for approval later this year. This new version is essentially a maintenance revision, with no new language features. The VHDL working group has started collecting requirements for language enhancements to be included in the next revision. A task group within the VHDL working group is also writing a standard for a programming language interface for VHDL simulators and should have a draft ready toward the end of this year